Deep Brain Stimulation (DBS) has become a technique for the treatment of movements disorders such as Parkinson's, essential tremor and dystonia as well as obsessive compulsive disorders and epilepsy. DBS has replaced thalamotomy or lesioning, and pallidotomy as a procedure in the last four to five years. It has proved very effective and as a procedure, has been recognized by the FDA. At the present, the cost of surgery and implants is extremely expensive (as much as $80,000 for bilateral implants), however it does improve the quality for life for patients and gives them an ability to be independent. Alternative procedures for the above identified tremor disorders include neuronal transplantation and growth factor infusion, though these procedures have not yet produced the clinical results as has DBS.
One of the critical steps during DBS surgery is locking of the head in a stereotactic headframe for locating the lead at the final position of the electrode implantation. Several hours of cranial mapping lead to the selection of this site, which is critical to the success of the procedure. In order to assure accurate location and adequate locking of the electrode on the cranium, the periphery around the cranial punch must be carefully prepared such that the plastic cap housing the connection has an absolutely concurrent contact with the skull at the site. Manual preparation of the surface is time consuming and irreparable damage of the skull is a continuing concern. Manual preparation requires repetitive test mounting of the electrode cap, which requires precious time and components are not infrequently accidentally dropped, further adding to the delay and cost. The present invention enables a quick, precise preparation of the surgical site, overcoming the need for test mounting, lost time and lost parts, while delivering predictable stability to the electrode fixation. The inventive drill bit assures a planar surface around the burr hole on the curved, irregular skull surface. By providing the enhanced cranial base and cap mounting in the DBS procedure prevents skin erosion due to cap/lead extrusion. Often such extrusion causes infection and may result in the later extraction of the cap and lead. Further, the optimized mount of the cap and lead ensures a smooth layer of skin over the cap and an enhanced cosmetic effect.
Representative devices for performing the cranial perforation are as follows. Each listed document is hereby incorporated herein in its entirety.
U.S. Pat. No. 5,135,532 for a Drill Head Assembly for Cranial Perforators illustrating inventive cutting flutes;
U.S. Pat. No. 5,007,911 for a Drill Head Assembly for Cranial Perforators illustrating particular drill head construction and drive mechanism;
U.S. Pat. No. 4,951,690 for a method of drilling through bone structure;
U.S. Pat. No. 4,884,571 for a cranial perforator with a reentrant cutting segment;
U.S. Pat. No. 4,803,982 for an improved camming structure for a cranial perforator drive;
U.S. Pat. No. 4,699,550 for a safety disengagement mechanism for a cranial drill to prevent over drilling; and
U.S. Pat. No. 4,600,006 for a drill bit including an inner and outer drill mechanism and a clutch for stopping drilling action.
There is thus a need for a drill bit for cranial perforations having the following characteristics and advantages over existing art.